Car wont go past 120 mph and wont rev any further than 5500rpm

As title just taken it out for a blast and it will not go past 120 mph/5500 rpm in 5th on my own private road of course, but will quite happily boost to redline in other gears. It runs at 17.5 psi but seems to drop off to around 16.5 psi under load, not sure if this would cause the problem.
Any ideas guys.

mods so far are
ESL live mapped
TDo5 16g
yellow injectors
prova headers
decat pipe
fuel pressure regulator
induction filter
Baileys dump valve
Walbro Fuel Pump


Cheers Andy

May seem daft,
But if it's an Import, has it had the speed limiter removed.

Jap cars are limited to 180kph/112mph and may be that that cutting your speed down.

Then hopefully it's just a case of getting a good speedo converter which also removes the speed limiter.

is it throwing up the cel light? did it feel 'hesitant'? possibly going into safe mode for some reason. wouldnt be booting it myself until you get it checked out.

agree with Kushbex, it will be speed limiter, the delimiters are dead simple to fit on the pre 96 cars.

Its had the limiter removed as i have hit 140 before, and its not throwing any codes up.
The gearbox was replaced a few days ago but can't see how this would cause a problem please feel free to tell me if im wrong.

Cheers Andy

You havnt had a close ratio box fitted, its rapid through the gears but tops out lower down?

Hello Stevie, no the other way round was told the gears in this are taller therefore increasing the speed.
But even if it was a close ratio box surely it would still hit the limiter in 5th and not stay at 5500 rpm.

Cheers Andy

mitchsti wrote:

Hello Stevie, no the other way round was told the gears in this are taller therefore increasing the speed.
But even if it was a close ratio box surely it would still hit the limiter in 5th and not stay at 5500 rpm.

Cheers Andy

Im sure Jonny Gav might be able to shed light on it, close ratio box will lower your top end so you wont get to redline in 5th. Unless 5th gearing was changed maybe.

just figured with it restricting rpm, maybe going into safe mode. did on mine when knock sensor started working its ticket *awaits abuse lol*

has whomever fitted the box refitted the delimiter as it is fitted between the speedo cable and gearbox cable???

Hope they didn't leave it on the old gearbox as this has been known to happen.

Does your car read kph or mph on the speedo?

the limiters fitted as i only removed the cable from the box

drew wrote:

the limiters fitted as i only removed the cable from the box

Drew It cant or should'nt have a limiter fitted as i have hit 140 mph several times previously.